The successful delivery of a pharmaceutical to a patient is of critical importance in the treatment of disorders. However, the use of many clinical drugs with known properties is limited by their very low water solubility. As a result of low water solubility these drugs must be formulated in co-solvent pharmaceutical vehicles, including surfactants. These surfactants have been shown to lead to severe side effects in humans that limit the clinical safety of these drugs and therefore the treatment of several disorders.
For example, camptothecin is a natural product isolated from barks of the Chinese camptotheca tree, Camptotheca accuminata. It has been shown to have strong anti-tumor activity in several in vivo animal models including major tumor types such as lung, breast, ovary, pancreas, colon and stomach cancer and malignant melanoma. The serious drawback of camptothecin is its very limited water solubility. For biological studies it is necessary to dissolve the compound in a strong organic solvent (DMSO) or to formulate the drug as a suspension in Tween 80:saline, which is an undesirable drug formulation for human therapy. Recently two analogs of camptothecin with moderate water solubility have been approved in United States for treatment of advanced ovarian cancer (Hycamtin) and colorectal cancer (Camptosar).
Other drugs, like camptothecin, that have similar problems are cyclosporin A (CsA), propofol, etoposide and Vitamin E (alpha-tocopherol). Like camptothecin, CsA has within its structure a sterically hindered alcohol, a secondary alcohol in this case. CsA is formulated in a CremophorEL/ethanol mixture.
An example of a sterically hindered, poorly water-soluble phenol is propofol, an anesthetic. Propofol is formulated for i.v. clinical use as a o/w emulsion. Not only is propofol poorly water soluble, but it also causes pain at the site of injection. The pain must be ameliorated such as with lidocaine. Moreover, because the Propofol is formulated as an emulsion, it is difficult and questionable to add other drugs to the formulation and physical changes to the formulation such as an increase in oil droplet size can lead to lung embolisms, etc.
U.S. Pat. No. 6,204,257 describes a water-soluble form of alcohol and phenol containing drugs such as camptothecin and propofol. With respect to camptothecin, compounds are phosphonooxymethyl ethers of camptothecin in the form of the free acid and pharmaceutically acceptable salts thereof. The water solubility of the acid and the salts facilitates preparation of pharmaceutical formulations.
However, the methods of making the water-soluble form of alcohol and phenol containing drugs described in U.S. Pat. No. 6,204,257 are complicated and utilize expensive and carcinogenic reagents. For instance, the synthesis of O-phosphonooxymethylpropofol requires 6 steps as summarized in the reaction scheme below.

It is desirable to have a process that is shorter and does not use carcinogenic or expensive reagents.